Method of making concrete blocks



Dec; 18, 1934.

F. J. STRAUB METHOD OF MAKING CONCRETE BLOCKS Filed Oct. 20, 1931 2Sheets-Sheet l A TTORNEY.

T. m E m Q 6%& m (B Q Wm 6 0 Z Dec. 18, 1934.

F. J. STRAUB METHOD OF MAKING CONCRETE BLOCKS 'ATTORNEY.

2 Sheets-Sheet 2 Filed Oct. 20, 1951 Patented Dec. 18, 1934 UNITEDSTATES- 1,985,115 METHOD OF MAKINGLCONCRETE BLOCKS Francis J. Straub,NewKensingtomfa.

Application October '20,

1931, Serial No. 569,908

3 Claims. (01. 25-155) My invention consists of an improvement in theprocess and manufacture of building blocks or the like made of pressedaggregate.

In such blocks the article is formed from a suitable aggregate as sand,gravel, vcinders, or other suitable material, mixed with cement andwater and pressed into form Within a shaping mold. Y r

Ordinarily such blocks, of well known standard construction, areprovided with core openings clear through their body portion from toptobottom. While such core openings are ordinarily of considerableadvantage and utility, there are certain conditions of use andapplication in which they are objectionable because of extendingentirely through the block. For instance, in the building of a wall withcomplete core openings extending vertically from bottom to top, theopenings provide cavities into which more or. less mortar or othercementing material is apt to be deposited, resulting in loss. .Also,when a wall is laid up with the core openings continuously registering,there are a series of flue-like openings from bottom to top of eachblock, continuously through the wall.

It has been recognized as a desirable feature that in some cases thecore openings should be segregated in each block, forming dead airspaces, and with a continuous covering top at the upper side of theblock. Heretofore, the formation of such a closing wall has not beenaccomplished successfully, due to the frequent collapsing or rupture ofthe wall in separating the block from the terminal end of the core.While it is desirable that the core opening should'extend through thebody of the block and terminate as closely as possible to the oppositeouter surface, the formation of such a covering top, especially with anaggregate of usual plasticity and fragility, has been difficult andimpossible in continuous operation with the resulting disturbance orcollapsing of the core top wall.

In the practice of my invention I provide means for forming the coreopening in connection with a core terminal capable of rotation wherebyto effect disconnection or severance of the core top from the under sideof the desired outer wall. By so doing, there is no sufiiciently strongadherence or suction, thus enabling separation of the formed block fromthe core. The invention is particularly applicable to the making of suchblocks in a press mold, as distinguished from a tamp mold, and will bereadily understood from the following description of the processfollowed with one preferred form of machine.

In the drawings:

Fig. 1 is a plan view ofa press mold showing the core forming elementsin position;

Fig. 2 is a vertical sectional view on the line II-II of Fig. 1 showingthe aggregate in pcsi tion within the mold around the cores, prior tothefinal pressing operation;

Fig. 3. is asimilar view showing the pressing head or platen of thecores iii-depressed position;

Fig. 4 is adetail view of .the rotating mechanism for'the coreterminal,just prior to release of pressure; v g

, Fig. 5 is a plan view of Fig. 4;

Fig. 6 is a view similar to Fig. 4 after release of pressure androtation of the core terminal;

Fig. 7 is a sectionalperspectiveview of a block resulting from thepractice of my invention.

In the drawings, 2 is the surrounding forming mold of conventional formand dimensions for the making of, for instance, an 8 X 8" x 16 block.Mold 2, which may be provided with a suitable interior lining, as shown,is mounted on the bottom plate or base 3 and is provided with aresiliently mounted bottom board or base 4 between the base 3 and theusual pallet 5. :25

Base 4 is mounted upon a series of supporting springs 60f any suitableconstruction whereby it may be depressed to the desired extent'underpressure of the aggregate from the pressing head or platen 7 The latteris provided with a central stem or rod 8 or other suitable construction,and is-actuated by well understood mechanism not herein necessarilyfurther shown. I

For the purpose of providing the closed top core opening or openings Iutilize one or more sheet metal cores!9 secured to base 4,"as at 10, andprovided at their upper ends with inwardly inclined terminal tops 11.The main cores as 'thus made are preferably rectangular, in form,

or of modified generally rectangular shape as de- 40 sired, and theinner edges of the terminals 11 are curved to provide a circular opening12. Within such opening, and closely interfitting therein, is thecircular slightly coniform terminal disk 13, for partial rotation withinthe annulus 12. Disk 13 is secured to the upper end of a stem 14 whichextends downwardly through the depressible base 4 and stationary base 3.

The disk 13 is also preferably provided with a downwardly extendingguiding shell 15 and a transverse bearing washer 16 resting upon aseries of rolling balls 17, for rotation on the upper surface of base 4,Stem 14 extends downwardly through bases 4 and 3 for guiding engagementthereby, so that when head 7 is lowered on the 2 upper surface of thefilled-in aggregate, it will compress the main body of the block againstsupporting resistance of the relatively stationary pallet 5 and willdepress terminal 13 with the outer core member 911 as base 4 is loweredagainst the re-acting pressure of springs 6.

It is desirable upon release of pressure of head 7, and prior to removalof the finished block by elevation of base 4 by the usual well knownmechanism, that terminal 13 be rotated a sufficient amount to effectcomplete separation and avoidance of suction adherence between theterminal and the inner under face of the pressed aggregate forming thecore covering wall a of the block A.

For such purpose I have provided a laterally acting turning arm 18extending from post 14, or from a bracket 19 thereon, by which, when'arm18 is thrust around in the manner of alever, it will rotate the post andterminal 13 a sufficient distance to effect the desired'separation.-Such operation is facilitated upon release of pressure of head 7 andreduction of frictional resistance by the pressed aggregrate against thecore top.

Extending upwardly from base 3 is a bracket 20 having an overreachinginclined guiding or cam arm 21. Pivotally mounted at the upper innerside of bracket 20, as at 22, is a shifting arm 23, between which andthe bracket is a spring 24 of sufficient strength to thrust arm 23outwardly against lever arm 18 upon termination of the fric-' tionalresistance against top 13.

The spring action thus applied will rotate the post 14 and its capimmediately upon release of the pressure of head '7 and simultaneouslywith the re-acting pressure of springs 6. Such springs thus effect theinitial upward movement of the formed block and the main core 9, theterminal 13 and post 14 moving upwardly at the same time and rate to alimited extent, as in Fig.2.

At the termination of such upward movement of the post, arm 18, whichhas been thrust outwardly to the position shown in dotted lines in Fig.5, will have been thrust into contact with the lower inner inclined faceof fender 21. Then, upon the upward movement of post 14 continuing byaction of springs 6, the inclined fender 21 acting as a cam, it willeffect reverse rotation of the post and its cap, bringing the arm 18backwardly to its original position, at a correspondingly higher level,as indicated at 18a, Fig. 4.

Prior to upward movement of bottom board 4 it is temporarily heldagainst lifting spring pressure by any suitable means, as latches 25pivotally mounted on pins or rods 26 and adapted to engage arrestingshoulders 27 of base 3. Latches 25 may be manually released andre-engaged by rotating rods 26, or by any suitable automatic mechanismas preferred.

,ing a closed top core In raised position cap 13 will therefore havebeen positively thrust in one rotating direction and then in the otherby the corresponding rotations of the post. The block being then removedupwardly from the mold by usual elevation of pallet 5, readily separatesfrom the core because of the negative vacuum conditions and reducedfriction and adhesion. The formed block may thus be readily pushedupwardly from the mold, which is then charged with fresh aggregate andthe operation just described is repeated..-

The construction of the machine and the advantage of its method ofoperation, and especially of the resulting product, will be readilyundersto'od and appreciated from the foregoing description. It iscomparatively simple, economical, capable of normally rapid productionand ouput, and results in a cored block having a comparatively thinsurface wall at the top of undisturbed normally strong condition,capable of hardening by either natural or artificial evaporation.

It will be understood that the method may be utilized in making a singleor plural core opening block, and that the machine may be variouslymodified in construction and detail design by the skilled mechanic toadapt it to various shapes, dimensions or designs of blocks, slabs,etc., and that all such changes are to be understood as contributing tothe invention within the following claims.

What I claim is:

1. In the manufacture of concrete building blocks of plastic aggregatethe method of forming a closed top core aggregate against a fixedresistance and around a receding inner forming surface, releasingpressure on the aggregate, and then imparting rotary wiping treatment tothe inner surface of the core top.

2. In the manufacture of concrete building blocks of plastic aggregatethe method of formconsisting in pressing the aggregate against a fixedresistance and around and against a receding inner forming surface,releasing pressure on the aggregate, and then imparting rotary wipingtreatment to the inner surface of the core top.

3. In the manufacture of concrete building blocks of plastic aggregatethe method of forming a closed to-p core consisting in pressing theaggregate against a fixed resistance and around and against an innerreceding Wall-forming surface, releasing pressure on the aggregate,maintaining the inner wall-forming surface stationary, and thenimparting rotary wiping treatment to the inner surface of the core top.

FRANCIS J. STRAUB,

consisting inpressing the

